Assymetrical Clipping

[Chistopher]

I was messing around with diodes this weekend and I noticed that at least in a hard clipping arrangement at least, assymetrical clipping makes a minimal difference over symmetrical. An LED paired with a germanium diode sounds mostly like an LED for example. I'd assume it has to do with a 1.4v signal being so much louder than a 0.35v signal. The smaller one adds a little texture and lowers the output a little, but it's mostly the bigger diode doing the heavy lifting.
Oh, as a side note, for those of you who tweak pedals. Make sure that you remember that no matter how much gain you put in your circuit, it's never going to get louder than the clipping diodes allow it to. In a soft clipped distortion with 0.7v diodes, the output amplitude compresses heavily after you cross the threshold voltage, but can still get louder than +/- 0.7v. A hard clipping arrangement however, will never go higher in amplitude than 2 × 0.7 = 1.4v. Boosting a hard clipped circuit either through internal modding or putting a clean boost in front of it serves no purpose other than making your distortion more saturated.

This is why boost pedals go after distortion pedals. If you want to test this. Set the maximum gain on your DS-1, set the volume wherever you want, and then experiment what it sounds like with a Klon set at maximum gain and volume settings into it. It will sound different, but the volume won't change. The maximum output a stock DS-1 has is 350 mV, regardless of what you put into it .

This has been my Ted Talk for the day

edit: for reference a single guitar note is usually between 25 and 45 mV

[Rex_Rocker]

The maximum output a stock DS-1 has is 350 mV, regardless of what you put into it .

edit: for reference a single guitar note is usually between 25 and 45 mV

I guess it depends on what mV readings a loud strum on a guitar is, but I bet it goes well over 350 mV. Especially on a high output pickup.

My personal gripe with a DS-1 is that no matter if you crank the output volume, the sound is quieter than a clean humbucker played hard. Like by a lot. I hate that. I hate switching to a distorted sound that's supposed to be loud and obnoxious and have it be quieter and tinnier than the clean sound. It's pretty clear to me the DS-1 came from a time when 99% of what people were playing were T-Tops, PAFs, or other vintage output pickups.

I'd be willing to bet even a PAF-type strummed hard peaks measurably higher than a DS-1, except the DS-1 is more compressed, so it will appear louder. But for strong pickups on a clean channel, IMO the DS-1 is unusable.

[Chistopher]

My Custom Custom measured strumming an open E pretty hard at like 500 mV peak with the sustain dropping off to about 150 mV. CC's are not loud by any stretch, but the pickups they had back in 78 were even quieter. Pre 84 DS-1's were quite louder than the ones we had today, because they had 1S2473 diodes and didn't clip as much. By my math the old ones could put out about 600 mV. I've never had my hands on one with the original magic diodes though, so I can't confirm.

Now EMG claims their pickups their pickups put out over 1 volt just on the attack of a plucked note, so the gain control on a DS-1 would serve as a compression knob more than anything. And not a very good one at that. I question that figure because that's loud enough to where one could drive a completely passive distortion circuit into some pretty hard clipping.

Another thing worth noting is that because most of A DS-1s EQ curve comes from the tone control, which is after the clipping stage, the louder a signal you send into a DS-1, the more the output will follow the response curve of your tone control.

[Rex_Rocker]

I'm not sure if EMG's actually put out what EMG advertises them at.

I have recorded DI's with EMG's and hot and vintage-output passives. I don't have mV readings, but have a relative idea of the dBu's they peak at (not really absolute values, but relative to each other). Mid output and over passives peak higher than EMG's (at least at 9V), it's just that EMG's clip internally, so they feel and are perceived louder than they actually measure at. However, if you really want EMG's peaks to actually come through past the preamp crunching up, running at 27V, they don't actually feel or are perceivably louder than when running at 9V. They're just less compressed with a stronger attack.

That being said, I'm sure a Duncan Distortion still peaks higher than an EMG 81 at 27V. The EMG 81 is not that hot, IME. While they're technically all the same output because they run on the same preamp, the EMG 85 is louder. So is the 57. And the JH-B.

[Chistopher]

Yeah, mV output of a pedal is definitely useful as a metric if you're talking about how loud a pedal can get, but to measure the output of a pickup it's kind of less useful. It's dependent on how you setup the pickup, what strings you have, how you're playing, what you're playing etc.

Even if the maximum output of a pickup when you slam a chord ends up being 1 V, that's just at the initial attack, it very quickly levels out to a fraction of that. This is where compression comes in and why high output pickups feel more compressed than low output ones. If your sustain comes in at 300 mV and the pedal can't put out more than 350 mV, that's a problem. Even if you're fine putting a boost after it, that level of compression can be a big detriment to your performance. But for somebody who's just learning to play guitar in their basement on moderate output pickups who just use the volume knob to find unity (after all the DS-1 is like #1 distortion beginners go to), it will work fine.

[Chistopher]

It would appear that a 2N7000 transistor has a body voltage of 0.7v to 1.1v meaning that if you use the gate and source pins as you would a diode, it could get me right where I want at roughly 0.9v